In each of the following questions, a group of three numbers/symbols is given in each option. Identify the group that does NOT follow the same pattern as the others.

Correct — D. Each term is a letter followed by its alphabet position (K = 11, I = 9, G = 7).

Rule: the letters step back 2 each time, so the numbers fall by 2.

K11 → I9 → G7, M13 → K11 → I9 and O15 → M13 → K11 all fall by 2.

N14 → K11 → H8 falls by 3 at each step, so option (d) breaks the pattern.

Why the others are wrong

• (a)
  K11 : I9 : G7 — K11 : I9 : G7 steps back 2 twice, K to I and I to G, and each number is its letter's position. It follows the rule.
• (b)
  M13 : K11 : I9 — M13 : K11 : I9 falls by 2 at each step, with M = 13, K = 11 and I = 9 matching their positions.
• (c)
  O15 : M13 : K11 — O15 : M13 : K11 also falls by 2 at each step, O to M to K, and every number is its letter's position.

Each term here pairs a letter with a number. First find how the two are linked: every number is the letter's position in the alphabet (A = 1 to Z = 26), in all four groups.

Then find how the terms move inside a group. Three groups fall by 2, skipping one letter each time. N14 : K11 : H8 falls by 3, skipping two.

Because the letter and the number move together, you can read the step from either strand.

Key facts

• Alphabet positions: G = 7, H = 8, I = 9, K = 11, M = 13, N = 14, O = 15.
• N to K and K to H are each 3 letters back.
• In options (a), (b) and (c) each step is 2 letters back.

Common traps

• Checking only that each number matches its letter, which all four groups satisfy.
• Comparing the groups with each other, when K11 sits in every one of them.

No directly related past PYQ was found.